ABSTRACT
Prosody plays a clear role in the auditory comprehension of narratives by aphasic listeners. Previous research, however, has pointed to questions regarding variables which increase task complexity (e.g., memory, reading level) and the influence of the severity of aphasia. This study examined the role of the severity of aphasia and linguistic complexity in narrative comprehension by aphasic listeners. Findings indicate that while all subject groups improved their auditory comprehension when emphasis was present, people with severe aphasia improved significantly more, but only in a low linguistic complexity condition. However, subjects had additional opportunity for improved performance in both low and high linguistic complexity conditions. These results pose additional questions about perceived task difficulty (and performance) and resource allocation strategies.
Subject(s)
Aphasia/psychology , Psycholinguistics , Speech Acoustics , Speech Perception , Adult , Aged , Aged, 80 and over , Analysis of Variance , Female , Humans , Male , Middle Aged , Severity of Illness IndexABSTRACT
The effects of speaking rate manipulation were examined in the velocity profiles of anticipatory lip protrusion gestures. Systematic changes in the shape, symmetry, and smoothness of the velocity profiles were observed as speaking rate was modulated across a wide range of self-selected rates, from fast to slow. Velocity profiles of movements produced at slower than normal speaking rates demonstrated greater asymmetry, irregularity, and differences in geometric form, compared to a normal and faster-than-normal rates. Subjects evidenced both inter- and intrasubject variability in the accomplishment of lip protrusion and rate manipulations. These results indicate that the velocity profiles of lip protrusion gestures do not necessarily remain invariant across changes in speaking rate. Rather, the data suggest that distinct movement patterns may be generated for slow speaking rates, with select characteristics of the movement pattern being maintained across normal and fast speaking rates.
Subject(s)
Speech/physiology , Adult , Female , Humans , Sound SpectrographyABSTRACT
The present investigation was designed to determine the influence of stressed word prosody on auditory comprehension by listeners with aphasia. Paragraph-length narratives were computer-edited to yield two conditions. In one condition, both the target words and the surrounding context were prosodically neutral; in the second condition, target words were stressed and the surrounding contexts were prosodically neutral. The paragraph-length stimuli were presented to 10 aphasic listeners and their comprehension was tested. Analysis revealed that prosodic information carried only by stressed target words, within paragraph-length stimuli, did not provide significant comprehension benefits to aphasic listeners. The comprehension improvement typically observed when paragraph-length narratives are stressed is, therefore, most likely due to prosodic cues that precede stress-bearing target words.
Subject(s)
Aphasia , Speech Perception , Speech , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle AgedABSTRACT
The differential effects of normal and emphatic stress on the auditory comprehension performance of 9 aphasic and 5 normal adults were assessed. As a partial replication of Pashek and Brookshire (1982), four paragraph-length stimuli were used from the original study. Each paragraph was presented twice. One version was recorded with one fact per sentence receiving normal stress, the second version with emphatic stress. Following each paragraph, subjects answered 16 "yes/no" questions about the eight target facts in each paragraph. This procedure allowed for direct comparison of performance across conditions on the same paragraph rather than on different paragraphs as in the original study. Analysis of the results revealed that the aphasic subjects demonstrated significantly better performance for stimuli presented with emphatic stress. In addition, no significant learning effect was observed over two repetitions of each paragraph. These data are interpreted as successfully replicating the findings of Pashek and Brookshire. The results suggest that emphatic stress plays an important role in auditory comprehension. However, the observed effect of emphatic stress should not be attributed solely to changes incumbent upon the stress bearing word. Alternative explanations are discussed.
